This invention relates to an apparatus for separating fiber material from a conveying air stream and advancing the fiber material to a fiber processing machine. The apparatus includes a substantially vertical feed chute having an upper, fiber inlet portion provided with a pneumatic fiber supply device having a stationary, air pervious screen for separating the fiber material from the conveying air stream which, stripped of the fiber material, is guided away from the feed chute.
In a known apparatus of the above type the air pervious screen is a horizontally arranged, downwardly open, semi-cylindrical shell and the intake channel which delivers the fiber-laden air stream into the feed chute merges into the feed chute with a tangential orientation toward the screen. The intake channel is connected to a fiber conveying fan, and the open outlet of the semi-cylindrical shell merges in the inlet opening of the feed chute. The fiber-laden air stream is guided along the inner cylindrical wall face of the screen, and then the fiber material drops into the feed chute. In order to increase the impact effect and thus ameliorate the dust removal from the mixture of fiber tufts and air, the power of the air stream may be increased by suitably adjusting the output of the fiber conveying fan. Such a procedure, however, has the disadvantage that the powerful air stream causes the fiber tufts to adhere to the inside face of the screen and thus accumulate there, clogging the screen and interfering with a proper fiber flow into the feed chute.